1. Field of the Invention
This invention relates to a shuttle machine used in a sealing press or other machine tools for transporting work pieces.
2. Description of the Related Art
FIGS. 1A-1C illustrate a conventional shuttle machine used in a sealing press for sealing product packages, such as blister-pack packages. The shuttle machine is also used in other types of machines for punching, gluing, embossing, stamping, etc. As shown in FIG. 1B, the sealing machine includes a press 12 having an upper platen 12a and a lower platen 12b, a support frame 14 situated between the two platens, and a sealing die 16 resting on the support frame 14. The sealing die 16 has a number of openings 16a into which the packages to be sealed are placed. The die 16 has two sections 16-1 and 16-2 substantially identical in size and shape, each section including one or more openings 16a. As shown in FIGS. 1B and 1C, the sealing die 16 can slide or move along guide rails 14a on the support frame 14 so that the two sections 16-1 and 16-2 are alternately located under the press 12.
In operation, two operators are located to the left and right of the sealing press, respectively. Note that terms such as “left” and “right” as used in this disclosure are with respect to the drawings. In an actual press or other machine tool, the operators may be located in the front and back of the machine (for example, the right hand side of FIG. 1B may be the front of the machine), or on the left and right sides of the machine. When the die 16 is moved to the right of the support frame as shown in FIG. 1B, the left-hand section 16-1 is located under the press and the right-hand section 16-2 is exposed and accessible to the second operator who is locate to the right of the sealing press. The second operator unloads packages that have been sealed and loads unsealed packages into the openings 16a in the right-hand section 16-2 of the die. Simultaneously, the press 12 operates to seal the packages that have been loaded into the left-hand section 16-1 of the die. When both the pressing and the unloading and reloading by the second operator are finished, the die is moved to the left (e.g. by a drive mechanism and initiated by one of the operators) into the position shown in FIG. 1C. At this position, the right-hand section 16-2 of the die is located under the press 12 and the left-hand section 16-1 is accessible. The first operator, located to the left of the sealing press, unloads the packages that have just been sealed and load unsealed packages into the left-hand section 16-1 of the die. Simultaneously, the press 12 operates to seal the packages that have just been loaded into the right-hand section 16-2 of the die. When both the pressing and the unloading and reloading by the first operator are finished, the die is moved to the right into the position shown in FIG. 1B.